1. Field of the Invention
The present invention relates to an ameliorating agent for dysmnesia (impairment of memory), particularly to an ameliorating agent for dysmnesia containing a derivative of pyrazolo[1,5-a]pyridine as an effective component.
2. Related Background Art
Recently diseases such as senile dementia accompanying dysmnesia have become a great medical and social problem as a result of elongation of human life.
Dysmnesia patients show a loss of intellectual ability, dysmnesia (namely, impairment of memory), impairment of abstract thinking, aphasia, apraxia, disorientation, etc. Such impairment of the fundamental function results from the disorder of formation of memory or of reproduction of the memory retained. However, no effective medicine therefor is said to be found at the moment, so that early development of the treating medicine is strongly desired.
The pyrazolo[1,5 a]pyridine derivatives represented by the general formula below found by Irikura et al. are known (Japanese Patent Publication No. 52-29318 corresponding to U.S. Pat. No. 3,850,941, U.K. Patent 1,378,375 and so on) to be effective for treatment of circulatory organ disease, prevention and treatment of bronchial asthma, antiallergic action for ophthalmic disease, and antirheumatic action, and still further be useful for treatment cerebrovascular disease: ##STR2## wherein R.sup.1 and R.sup.2 are independently hydrogen or a lower alkyl of 1-4 carbons, R.sup.3 is hydrogen or a lower alkyl of 1-3 carbons or a lower alkoxy of 1-3 carbons.
Such pyrazolo[1,5-a]pyridine derivatives, however, are not known to have an action of ameliorating dysmnesia until now.